Internal combustion engine



May 19, 1931. 1,805,540

5. B. BROWN INTERNAL COMBUSTION ENGINE Filed Jan. 7, 1930 Ale 8 47 I 5 ri \LLWL ah l Intake IN V! N TOR.

Patented May 19, 1931 UNITED STATES SAMUEL 3. BROWN, 01 ANGELES, CALIFORNIA.

ETERNAL COMBUSTION ENGINE' Application filed January 7, 1930. Serial No. 419,098.

This invention relates to an internal combustion engine of the two cycle opposed piston type.

An object of the invention is to provide improved means for adjustably varying the travel of a piston head in an engine of this type for the purpose of modifying the power out ut as desired.

further object of the invention is in general to simplify the construction of and controls for an adjustable engine of the type aforesaid.

A? still further object is to arrange the working parts in a superior manner with 5 respect tb compactness of structure, and at the same time to make them of sucha rugged character that they will endure heavy loads.

Other objects, advantages and features of invention may hereinafter appear.

Referring to the accompanying drawings which illustrate what is at present deemed 9 be a preferred embodiment of the inven- Fig. 1 is a side elevation of an engine cylinder provided with a pair of opposed pistons and including operating connections and adjusting means constructed according to the rinciples of the invention. In this view t e engine cylinder and pistons are shown in longitudinal mid-section.

Fig. 2 is a fragmental detail of said adjusting device shown in the upper portion of Fig. 1, looking from right to left of the latter vlew.

engine cylinder 5 is provided with two opposed pistons 6 and 7 between which is located the combined combustion and piston chamber 8. As viewed in Fig. 1 of the drawings, the engine cylinder 5 is supported by the engine frame 9 which in turn is mounted upon a base 10, it being understood that said base 10 may be constructed and arranged to have a pluralit of engine frames 9 and cooperating cylin ers 5 supported thereby. To the lower end of engine frame 9 is attached the usual crank case 9a. The engine frame 9 carries the downwardly inclined lower arm or bracket 11 and the upwardly inclined upper arm or bracket 12, the latter arm sup- Referring in detail to the drawings, the

porting said operating connections as will later be described. I

Said bracket 12 has secured thereto, by means of a bearing 14, a head or disc 15 which, in turn, is provided with a pivot stud 16 located eccentrically with relation to bearing 14, said stud 16 forming a pivotal support for the rocker arm 17. Disc 15 is formed integral with, or in fixed relation to, a radial arm 20 to the outer end of which is pivotally connected'an operating rod 21, said rod 21 being manually adjustable or being controlled by a governor (not shown).

To one end of the rocker arm 17 is connected, by the pivot 25, the connecting rod 26 of the pistpn head 7, the pin 27 connecting said rod 6 to saidpiston head 7. The other end of said rocker arm 17 is pivoted by r a pin 30, to one end of an extension rod 31, the other end of said rod 31 carrying a pivot pin 32 whereby it is connected both to a relatively short link 33 and to an additional link 34.

- Said link 33'has its other end pivotally connected at 35 to the outer end of the aforementioned arm or bracket 11.

The piston head 6 is provided with a connecting rod 40 to which it is connected by the pivot pin 41, the other end of said connecting rod 41 being fixed to the crank portion 42 of crank shaft 43. Said crank portion 42 1s provided with the pin 44 of the crank shaft to which the adjacent end of connecting rod 40 is pivoted, the aforementioned link 34 being also pivoted at one end to said crank shaft pin, the other end of said link 34 being pivg oted to the adjacent end of the extens on arm 31.

The upper end of the combined combustion and piston chamber 8 is provided. with the intake ports 45 which communicate with the 9 annular intake passage 46, the latter passage leading to the carburetor 47. The lower end of carburetor 47 is furnished with the fuel feed pipe: 48 and the central portion of said carburetor communicates with an air supply or; 49 through which air is forced by means of a blower 50. Said blower 50 is in. turn supplied with air from a valve casin 51 within which is an 'air valve (not shown% having a radial arm 52 operated by a rod 53.

,cated at the mid-length of the piston chamber 8. At the lower end of Fig. 1 is diagrammatically indicated and approximately labeled the portions of the travel of the pistons during which intake, exhaust, compression and expansion are taking place within the piston chamber.

The outer end portion of link 33 as shown in the lower right hand portion of Fig. 1, may be provided with a pivot slot 33a whereby said link can be shortened to move the floating oint of which 32 is the pivot point a farther distance from the frame 9 of the engine, during the reciprocation of the piston heads. It is to be understood that the extension arm 31 and the link or rod 34 pivoted to the lower end of said extension arm need not in every instance be made as separate parts, but a single rod may ofttimes be employed to connect the pivot withthe pin 44 of the crank shaft.

In operation, assuming the position of the pistons to be that shown in Fig. 1 wherein they have both reached the outer limit of movement and both the inlet ports and the exhaust ports are uncovered, continued right hand rotation of the crank shaft 43 will result in the lower piston 6 being forced upwardly, and at the same time, through the operation of the rods 34, and 31 and rocking arm 17 the upper piston 7 will be forced downwardly. This movement will proceed I until the two pistons have reached the dotted line positions indicated in Fig. 1 thus compressing between them the fuel mixture which will then be ignited from the ignition plug 63 by the timing mechanism (not shown). Thereupon the two pistons will be forced away from each other in opposite directions and, near the limits of their outward travel, the exhaust ports 60 will be opened slightly before the intake ports 45,-are opened. This will cause an outru-sh ofthe products of combustion through the exhaust ports 60,thus partly scavenging the combustion chamber before the intake ports 45 are opened. Im-v mediately upon the opening of intake ports 45 fuel mixture will rush into the upper end of the combustion chamber from the carburotor 47 owing to the fact that the blower 50 is kept in continuous operation thuscausing the combustible mixture to press against the sides of the upper piston 7 and consequently to rush in around the end of said piston as soon as it moves up sufliciently to allow this to occur. After-this has taken place the pistons have reached the position shown in Fig. 1 and the cycle of operations already described will repeated.

Normally the inner limits of travel of the pistons 7 and 8 will be at the lines and 6a respectively. When it is desired to adjust the engine to carry a lighter load the pivot 16 whereon the rocking arm 17 is supported may be moved to the dotted line position of Fig. 1, this adjustment being accomplished by moving the arm 20 to the dotted line position of said view. The effect of this adjustment will be to cause the inward movement of the piston 7 to be arrested at the line 7 1; instead of line 7a, thus affording a smaller compression area between the opposed ends of the pistons 6 and 7 when they are at the inner limits of travel.

A further result of this adjustment will be to cause the line 7:2: to coincide with the inner face of the piston 7 at the outward limit of its movement for this adjustment. Hence, at such time, it will uncover only the lower portion of the inlet ports 45 and will consequently allow only a comparatively small part of normal combustible mixture to be blown in at each stroke of the piston 7. The total efiect therefore of the adjustment described will be, decrease of combustible mixture admitted accompanied by compressing the amount of mixture which enters into a smaller space.

The adjustment of the pivotal support of the rocking arm 17 will not afi'ect the limits of the travel of the lower piston 6 because -the connecting rod 40 of the latter piston is secured to the crank portion of the crank shaft 43.

Claims:

1. In an internal combustion engine, two opposed pistons, a piston cylinder common to said pistons, a piston rod pivotally connected to each of said pistons,a rocker arm having a pivotal support between its ends, a rocking head, a fixed support for said rocking head to which the latter is pivoted, said rocker arm being pivotallyconnected with said head at a ppint eccentric to the pivotal mounting of the latter, means to adjust the position of said head upon its pivot to vary the location of the pivotal support of said rocker arm, one end of said rocker arm being pivotally connected with the outer end of one of said piston rods and the other end of said rocker arm being operatively connected with the outer end of the other of said piston rods to coordinate the movements of said pistons, and a crank shaft operatively connected with said pistons.

2. In an internal combustion engine, two opposed pistons in substantially axial alignment with each other, a crank shaft operatively related to said pistons, and means to coordinate the movements of said pistons to cause them both to move away from each other during one portion of the cycle and toward each other during .another portion thereof, said coordinating means comprising signature.

SAMUEL B. BROWN. 

